243145021109 has 4 divisors (see below), whose sum is σ = 249716508204. Its totient is φ = 236573534016.

The previous prime is 243145021099. The next prime is 243145021139. The reversal of 243145021109 is 901120541342.

243145021109 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 118904280625 + 124240740484 = 344825^2 + 352478^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-243145021109 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243145021139) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3285743492 + ... + 3285743565.

It is an arithmetic number, because the mean of its divisors is an integer number (62429127051).

Almost surely, 2^243145021109 is an apocalyptic number.

It is an amenable number.

243145021109 is a deficient number, since it is larger than the sum of its proper divisors (6571487095).

243145021109 is an equidigital number, since it uses as much as digits as its factorization.

243145021109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6571487094.

The product of its (nonzero) digits is 8640, while the sum is 32.

The spelling of 243145021109 in words is "two hundred forty-three billion, one hundred forty-five million, twenty-one thousand, one hundred nine".